LF: RAM Upgrade possibility


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LF: RAM Upgrade possibility




Yes.  The extra RAM is already in the TI-92 -- they just decided not to
allow access to it.  Additionally there's a Sun UltraSPARC compatible chip
running at 100 BIPS in there that is also currently unused as part of a
satellite up/downlink system near the left set of batteries.

"Fargo runs machine language by sending a backup that is so big that it
wraps around to the beginning of memory, modifying entries in the exception
vector table to point to a routine stored in RAM instead of the vector
routine in ROM. Since the TI-92 will be receiving the backup at the same
time as it is overwriting the vector table, at some point the backup
receiving routine will trigger a vector that has been already
modified. Instead of running the routine is was supposed to, it will
trigger the routine stored in RAM that was transferred earlier in the
backup. This happens at about 99%, at which point the Graph Link software
will report a timeout error and state that the the backup has failed. It
couldn't be more wrong!" -- backups.txt.  Nothing to do with ROM.

-Kevin
khuber@mr.net

Jake Robb writes:
 > I heard mention that the RAM upgrade is actually a ROM revision which
 > tells the calculator how to access the extra RAM.  I wonder, since we
 > can hack the ROM to put Fargo in it, why couldn't we hack it and put the
 > extra code in there?  I couldn't do it myself, but maybe whoever figured
 > out how to put Fargo in there could do it.


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